Guarded surgical scalpel with scalpel blade remover

ABSTRACT

This invention relates to an improved guarded surgical scalpel having a movable guard that can be retracted to expose the blade and that can be extended to cover the sharp cutting edge of the blade. The guard is telescopically mounted inside the blade handle and includes a deflectable top wall portion that holds a detent pin or that defines a radially extending flange. This detent pin or flange engages a slot having upturned ends formed in at least one side wall of the blade handle. The detent pin or flange is biased upwardly into the upturned ends of the slot to hold the guard in the retracted or extended position. The blade can include a tang having a notch formed therein. The distal end of one sidewall of the guard can be formed with a complementary notch such that when the distal end of the sidewall of the guard engages the proximal end of the blade, forward movement of the guard forces the blade off of the scalpel. A lifter wedge is provided to urge the proximal end of the blade away from a blade carrier into engagement with the distal end of the sidewall of the guard.

This application is a continuation-in-part of application Ser. No.08/379,245 filed Jan. 27, 1995, now U.S. Pat. No. 5,752,968, that is acontinuation-in-part of application Ser. No. 08/328,996 filed Oct. 25,1994 that issued as U.S. Pat. No. 5,620,454 on Apr. 15, 1997.

BACKGROUND OF THE INVENTION

The present invention relates to a surgical scalpel and, in particular,to a surgical scalpel having a retractable blade guard to protectagainst inadvertent nicks or cuts during handling and especially duringa surgical procedure in an operating room. In addition, this inventionrelates to a unique mechanism for removing the blade from the handle fordisposal either during or at the end of the surgical procedure.

Scalpels are regularly used by surgeons and other health careprofessionals for making incisions in a patient during an operatingprocedure. Typically, a nurse hands the scalpel to the surgeon in apredetermined orientation so that the surgeon can grip the scalpel'shandle without taking his or her eyes away from the patient. If thenurse accidentally touches the scalpel when it is on the table, does notpay close attention when picking up the scalpel or if the predeterminedorientation is not closely followed when the scalpel is transferred tothe surgeon, the nurse's or surgeon's hand may be cut or nicked by theblade of the scalpel. The same hazard of being cut or nicked by theblade may be encountered when the surgeon transfers the scalpel back tothe nurse.

These nicks or cuts are uncomfortable and distracting. In addition, theymay result in blood or body fluid exposure between the patient and thesurgeon or other healthcare professionals in the operating room orelsewhere in the hospital. This may lead to the spread of infectiousdiseases between the patient and the healthcare professional. Concernover this situation has become especially acute because of such diseasesas acquired immune deficiency syndrome, i.e. AIDS, and hepatitis.

While surgical gloves aid in reducing the chances of being cut during asurgical procedure, these gloves are not foolproof. And even when twosets of gloves are utilized, full protection is not afforded to thehealthcare provider because the scalpel blade can still cut through bothsets of gloves. Also, utilizing two sets of gloves reduces fingerdexterity by the surgeon and thus is distracting to the surgeon and caninterfere with the intended surgical procedure.

In view of the need for a surgical scalpel that can prevent or at leastminimize the chances of accidental nicks or cuts during handling,numerous guarded surgical scalpels have been recently designed.Unfortunately, these designs are deficient because they are cumbersome,difficult to use, may cause unwanted shielding or exposure of thescalpel blade prior to the need for such shielding or exposure or mayrequire considerable attention by the user to shield or expose theblade. In addition, these prior designs are deficient because they donot provide a safe and effective way for the blade to be removed fromthe handle either during or after the surgical procedure. Typically theblade tang has to be grasped by the user's hand or by a clamp and pulledfrom the handle. This procedure is not desirable because it exposes theperson attempting to remove the blade to the risk of being cut if theuser's hand is used to grasp the blade tang. And even if a clamp isused, this procedure is cumbersome at best.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a guarded surgicalscalpel that prevents or at least minimizes the chance that thehealthcare professional will be nicked or cut when the guarded surgicalscalpel is handled.

It is another object of this invention to provide a guarded surgicalscalpel that is easy to use and that can be operated by one hand of theuser.

It is yet another object of the invention to provide a guarded surgicalscalpel that will not allow the blade to be shielded or exposed prior tothe need to do so.

It is still another object of this invention to provide a guardedsurgical scalpel that can be used without the need for the user toobserve the movement of the guard or to place undue attention to itsoperation.

It is still a further object of this invention to provide a guardedsurgical scalpel that allows for the safe and effective removal of theblade from the handle after use.

This invention comprises a guarded surgical scalpel including a handle,a blade connected to the handle, and a guard telescopically mountedwithin the handle for sliding movement between a retracted position inwhich the blade is exposed for use and an extended position for coveringthe sharp cutting edge of the blade. A stop is provided between theguard and the handle for limiting the sliding movement of the guardwithin the handle. The stop preferably includes at least one pin mountedon the handle transversely thereof and received within a closedlongitudinal slot formed in at least one of the side walls of the guard.A unique detent mechanism is provided between the guard and the handlefor defining the extended position and the retracted position of theguard on the handle. The detent mechanism comprises a slot with upturnedends formed in at least one sidewall of the handle and a movable topwall formed in the guard to which a pin is connected or which has aradially extending flange formed therein. This pin or flange engages andrides in the slot formed in the handle. The top wall of the guard, andthus the pin or flange, are biased upwardly so that the pin or flange iscaptured in the upturned ends of the slot to prevent longitudinalmovement of the guard by the application of only a longitudinal force tothe guard by the user. The user, however, can move the guard by simplydepressing the top wall of the guard to move the pin or flange out ofengagement with the upturned ends of the slot.

The distal end of one sidewall of the guard is formed with a notch thatcomplements a notch formed in the proximal end of the tang of the blade.By merely aligning the notch on the sidewall of the guard with the notchon the blade tang, forward movement of the guard will force the bladeoff of the handle. Alignment between the notch on the sidewall of theguard and the notch on the blade tang is provided by a movable lifterwedge on the blade carrier. This lifter wedge can be urged between theblade tang and the blade carrier to lift the blade tang away from theblade carrier.

DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of this invention will beapparent upon consideration of the following drawings and detaileddescription. The preferred embodiments of the present invention areillustrated in the appended drawings in which like reference numeralsrefer to like elements and in which:

FIG. 1 is a perspective view of the guarded surgical scalpel of thepresent invention with the guard in a retracted position to expose theblade;

FIG. 2 is a perspective view of the guarded surgical scalpel of thepresent invention with the guard in a partially extended position andwith the guard shown in phantom in the fully extended position;

FIG. 3 is a cross-sectional view of the guarded surgical scalpel of thepresent invention taken along line 3--3 of FIG. 1;

FIG. 4 is a cross-sectional view of the guarded surgical scalpel of thepresent invention taken along line 4--4 of FIG. 1;

FIG. 5 is an exploded perspective view of the guarded surgical scalpelof the present invention;

FIG. 6 is an exploded side elevation view showing a portion of theguarded surgical scalpel of the present invention;

FIG. 7 is a side elevation view showing a portion of the guardedsurgical scalpel of the present invention with the guard in a retractedposition to expose the blade and with the notch on the blade alignedwith the notch on the guard;

FIG. 8 is a perspective view of another embodiment of the guard used inthe guarded surgical scalpel of the present invention;

FIG. 9 is a side elevation view of a portion of the present inventionwith the lifter wedge advanced between the blade and the blade carrier;

FIG. 10 is a side elevation view of a portion of the present inventionwith the lifter wedge in its unbiased condition;

FIG. 11 is a cross-sectional view of the guarded surgical scalpel of thepresent invention taken along line 11--11 of FIG. 10;

FIG. 12 is cross-sectional view of the embodiment of the guardedsurgical scalpel of the present invention taken along line 12--12 ofFIG. 9;

FIG. 13 is a top plan view of a portion of the guarded surgical scalpelof the present invention shown in FIG. 9;

FIG. 14 is a side elevation view similar to FIG. 9 but with a secondembodiment of the detent mechanism for holding the lifter wedge betweenthe blade and the blade carrier;

FIG. 15 is a side elevation view similar to FIG. 10 but showing thesecond embodiment of the detent mechanism for holding the lifter wedgebetween the blade and the blade carrier; and

FIG. 16 is an end elevation view of the guard taken along line 16--16 ofFIG. 14 showing the second embodiment of the detent mechanism forholding the lifter wedge between the blade and the blade carrier withthe spring arm connected to the lifter wedge shown in phantom in boththe biased and unbiased position.

DETAILED DESCRIPTION OF THE INVENTION

The guarded surgical scalpel 10 of the present invention includes ahandle 20 having a guard 30 telescopically received within handle 20 forlongitudinal sliding movement in handle 20. A blade carrier 40 ismounted on the distal end of handle 20 to allow a blade 50 to be fixedlysecured to the distal end of handle 20. Blade carrier 40 is mounted tohandle 20 by two transverse pins 41, 42 that extend across the width ofhandle 20. Pins 41, 42 can be bonded to blade carrier 40 and handle 20by any conventional means such as orbital riveting, chemical adhesive,ultrasonic bonding, welding or brazing.

Handle 20 has two parallel side walls 21, 22, a bottom wall 23 and aclosed proximal end 24. This configuration for handle 20 defines acavity 25 therein. Proximal end 24 of handle 20 is tapered to a thinportion to provide a blunt dissection tool that can be used during theoperating procedure. Side wall 21 of handle 20 preferably defines a slot26 that is aligned with a slot (not shown) formed in opposing side wall22. Each slot is generally parallel to the longitudinal axis of handle20. In addition, the ends of each slot have upturned portions 26'extending away from the main portion of the slot. It is to be noted thatthe configuration of slot 26 is a mirror image of the configuration ofthe slot formed in side wall 22. Preferably handle 20 is formed from 410stainless steel. However, 303 stainless steel or 420 stainless steelcould also be used. In order to have a comfortable and functionalproduct, handle 20 preferably has an overall length of about 4.180inches, an overall width of about 0.310 inches and an overall height ofabout 0.520 inches. Preferably the slots each have an overall length ofabout 1.875 inches.

Guard 30 preferably has two parallel side walls 31, 32 which areconnected by a proximal top wall 33 and a distal top wall 34. Preferablyside walls 31, 32 have a shape similar to that of a standard surgicalscalpel blade. Using this shape for side walls 31, 32 helps the user ofguarded surgical scalpel 10 intuitively to understand how to hold anduse guarded surgical scalpel 10. Preferably guard 30 is formed from 410stainless steel but 303 stainless steel or 420 stainless steel, can alsobe used. Because guard 30 slides past blade carrier 40 and handle 20,guard 30 is preferably treated by titanium nitride or chromium nitridevapor deposition. This treatment hardens the surface of guard 30 andprevents galling thereby ensuring smooth operation of guarded surgicalscalpel 10 over its useful life.

Side wall 31 defines an upper slot 39 adjacent to distal top wall 34along substantially the entire length of side wall 31 except for themost distal portion thereof. Side wall 32 also has an upper slot formedtherein (not shown) which is aligned with slot 39. It is to beunderstood that the configuration of slot 39 is a mirror image of theconfiguration of the upper slot formed in side wall 32. This allowsdistal top wall 34 to be flexed downwardly in a cantilevered fashion.Depressible distal top wall 34 carries a detent button 35 to facilitatedownward flexing of distal top wall 34. Alternatively, distal top wall34 can be formed with a bump 35' therein to facilitate downward flexingof distal top wall 34. See FIG. 8. A detent pin 36 is located adjacentto the proximal end of distal top wall 34 and may be bonded thereto bypress fit, welding or chemical adhesive. Alternatively and preferably, aradially extending flange 36' is formed along the proximal end of distaltop wall 34. See FIG. 8. By using radially extending flange 36' formedin distal top wall 34, a separate element, i.e. pin 36, does not have tobe secured to distal top wall 34. This facilitates the manufacturing ofguarded surgical scalpel 10. It is to be understood that detent pin 36and radially extending flange 36' preferably extend radially from bothsides of distal top wall 34.

Guard 30 is preferably mounted in cavity 25 of handle 20 for telescopicmovement therein and should be dimensioned to allow a tight yet movablefit therein. In order to allow such movement by guard 30, blade carrier40 is centrally mounted across the distal open end of handle 20 to allowa clearance on either side of blade carrier 40 for side walls 31, 32 ofguard 30. This arrangement requires a lower slot 38 to be formed in sidewall 31. Side wall 32 also has a lower slot formed therein (not shown)which is aligned with slot 38. It is to be understood that theconfiguration of lower slot 38 is a mirror image of the configuration ofthe lower slot formed in side wall 32. Pins 41, 42 engage the ends ofthe lower slots formed in side walls 31, 32 to limit the slidingmovement of guard 30 relative to handle 20. By placing guard 30 withincavity 25, detent pin 36, or radially extending flange 36', extends intoand rides in the slots formed in side walls 21, 22 of handle 20 and isbiased into the upturned portions provided at the ends of these slotswhen guard 30 is in the fully extended or the fully retracted position.The length of these slots formed in side walls 21, 22 of handle 20 isequal to the amount of travel of guard 30.

When detent pin 36, or radially extending flange 36', is located in theupturned portions at the ends of the slots formed in side walls 21, 22of handle 20, guard 30 is temporarily locked in the extended orretracted position. If the user were to inadvertently apply alongitudinal force to guard 30, detent button 35 or bump 35' when guard30 was in one of these positions, guard 30 would not move. In order tomove guard 30, a downward force must be applied to distal top wall 34,detent button 35 or bump 35' to move pin 36, or radially extendingflange 36', out of engagement with the upturned portions at the ends ofthe slots formed in side walls 21, 22 of handle 20. Thus, the chancethat the user would inadvertently shield or expose blade 50 prior to theneed to do so is minimized. In addition, because of the upward bias ofdistal top wall 34, and thus detent pin 36, or a radially extendingflange 36', the user will automatically know when guard 30 has beenmoved completely to the extended or retracted position by an audible"click" when pin 36, or radially extending flange 36', engages one ofthe upturned portions at the ends of the slots formed in side walls 21,22 of handle 20.

In order to allow the user to flex distal top wall 34 downwardly with acomfortable force, the distal portion of the upper slots formed in sidewalls 31, 32 of guard 30 should begin about 1.1 inches from the distalend of guard 30 when guard 30 is formed from 410 stainless steel. Ifguard 30 is formed from a softer material such as plastic this distancecould be greater. In addition, these upper slots should have a height ofabout 0.065 inches. These dimensions allow sufficient downward movementof detent pin 36, or radially extending flange 36', so it can be movedout of engagement from the upturned portions of the slots formed in sidewalls 21, 22 of handle 20.

Blade carrier 40 extends forwardly of handle 20 in a cleat 49 and has alaterally-extending longitudinal rib 49a provided with an externalgroove 48. Blade carrier 40 is preferably formed from 410 stainlesssteel. However, 303 stainless steel or 420 stainless steel, could alsobe used. Blade 50 has a longitudinal slot 51 which cooperates withgroove 48 and rib 49a to mount blade 50 on blade carrier 40, therebymounting blade 50 on handle 20. Blade 50 is relatively thin and verysharp and is "snapped" over rib 49a on blade carrier 40. As shown inFIGS. 6 and 7, blade carrier 40 may include a notch 45 formed thereinthat mates with another notch 59 formed in the blade tang 57. Inaddition, sidewall 32 of guard 30 can have a notch 37 that matches notch45. This configuration may be used, if desired, to ensure that only theappropriate blades are used with guarded surgical scalpel 10. Inaddition, this configuration provides another benefit. By slightlylifting blade tang 57, notch 37 of guard 30 can engage notch 59. Oncethese notches are engaged, guard 30 can be advanced distally to forceblade 50 from blade carrier 40. If desired, sidewall 31 could also havea notch that matches notch 35.

The embodiments of the guarded surgical scalpel of this invention shownin FIGS. 9 through 16 provide simple mechanisms to lift blade tang 57 toallow notch 37 to engage notch 59. A cantilever spring arm 46 is formedin blade carrier 40. The distal end of cantilever spring arm 46 includesa wedge shaped portion 47 that aligns with the interface between bladecleat 49 and blade 50. Preferably wedge 47 is formed with an angle α ofabout 30 degrees and dimension A of between about 0.125 inches and 0.313inches. Spring arm 46 and wedge 47 are arranged on blade carrier 40 sothat the tip of wedge 47 extends to cleat 49 in the unbiased condition.See FIG. 10. In this way, the tip of wedge 47 is already in theinterface between cleat 49 and blade tang 57. By moving cantileverspring arm 46 toward this interface by pushing button 46a, wedge 47causes blade tang 57 to move away from cleat 49 to facilitate engagementbetween blade notch 59 and guard notch 37. This arrangement of springarm 46 and wedge 47 allows the healthcare worker to remove blade 50without touching any part of blade 50 by simply advancing guard 30distally. Preferably, cantilever spring arm 46 is about 1 inch long andabout 0.125 inches thick. It is connected to blade carrier 40 via aflexural hinge to facilitate movement of wedge 47 toward the interfacebetween cleat 49 and blade tang 57.

Wedge 47 and blade carrier 40 are configured to provide a detentmechanism that holds wedge 47 in the interface between blade cleat 49and blade tang 57. Specifically, blade cleat 49 is formed with ashoulder 90 that engages the shoulder 91 formed between wedge 47 andspring arm 46. In this way, the user need not constantly squeeze springarm 46 to raise blade tang 57. Instead, shoulders 90 and 91 hold wedge47 in the interface between blade cleat 49 and blade tang 57 while blade50 remains on blade carrier 40. See FIG. 12. While blade 50 is connectedto blade cleat 49, blade 50 serves to force shoulders 90 and 91 intoengagement with one another. Once blade 50 has been removed from bladecarrier 40, shoulders 90 and 91 disengage to allow spring arm 46 toreturn to its unbiased position.

In another embodiment shown in FIGS. 14-16, the detent mechanism merelycomprises a shoulder 91' that holds the bottom of spring arm 46 in thebiased position so wedge 47 is in the interface between blade cleat 49and blade tang 57. See FIG. 14. Once guard 30 is advanced to eject blade50 from blade carrier 40, shoulder 91' no longer engages spring arm 46because shoulder 91' is extended past spring arm 46. This allows springarm 46 to be returned to its unbiased position. See FIG. 15 where springarm 46 is in its unbiased position and guard 30 has been retracted intohandle 20. Thus a new blade can be subsequently installed on bladecarrier 40.

Thus, it is seen that a guarded surgical scalpel is provided thatprevents, or at least minimizes, the chances for nicks or cuts duringhandling, that is easy to use and can be operated by one hand of theuser, that will not allow the blade to be shielded or exposed prior tothe need to do so, that can be used without the need for the user toobserve the movement of the guard or to place undue attention to itsoperation and that provides a simple, safe and effective way to removethe blade from the handle.

We claim:
 1. A method for removing a blade, having a proximal end, froma guarded surgical scalpel having a guard with a distal end and a bladecarrier for carrying the blade, comprising:lifting the proximal end ofthe blade from the blade carrier; engaging the proximal end of the bladewith the distal end of the guard; and moving the guard in a distaldirection to force the blade from the guarded surgical scalpel, whereinthe guarded surgical scalpel includes a wedge operably connected to theblade carrier and movable from an unbiased position to a biased positionbetween the blade carrier and the blade for lifting the proximal end ofthe blade from the blade carrier and further comprising the step ofmaintaining the wedge in the biased position until the guard is moved inthe distal direction.
 2. The method of claim 1 wherein the proximal endof the blade defines a notch and the distal end of the guard defines anotch that is complementary to the notch in the proximal end of theblade so the blade notch is engaged with the guard notch during theengaging step.
 3. The method of claim 1 further comprising the step ofmoving the wedge to the unbiased position after the guard is moved inthe distal direction.
 4. The method of claim 3 wherein the proximal endof the blade defines a notch and the distal end of the guard defines anotch that is complementary to the notch in the proximal end of theblade so the blade notch is engaged with the guard notch during theengaging step.
 5. A guarded surgical scalpel handle for holding a blade,comprising:a handle body a guard telescopically received within thehandle body for longitudinal movement with respect to the handle body;and a blade carrier extending from the distal end of the handle body,said blade carrier having a portion adapted to mount a blade, said bladecarrier further comprising a cantilever spring arm disposed to movetoward and away from the portion of the blade carrier.
 6. The guardedsurgical scalpel handle of claim 5 further comprising a blade defining aplane mounted to blade carrier such that movement of the cantileverspring arm toward the blade carrier in the plane of the blade urges theblade away from the blade carrier.
 7. The guarded surgical scalpelhandle of claim 6 wherein the blade includes a proximal end with a notchformed therein and the guard includes a distal end with a complementarynotch formed therein.
 8. The guarded surgical scalpel handle of claim 5further comprising a wedge at the distal end of the cantilever springarm.
 9. The guarded surgical scalpel handle of claim 8 wherein the wedgedefines a first shoulder with the cantilever spring arm and the bladecarrier defines a second shoulder for engagement with the firstshoulder.
 10. The guarded surgical scalpel handle of claim 9 furthercomprising a blade defining a plane mounted to the blade carrier suchthat movement of the spring arm in the plane of the blade toward theblade carrier urges the blade away from the blade carrier.
 11. Theguarded surgical scalpel handle of claim 10 wherein the blade includes aproximal end with a notch formed therein and the guard includes a distalend with a complementary notch formed therein.
 12. The guarded surgicalscalpel handle of claim 8 wherein the guard includes a shoulder toengage the cantilever spring arm to hold the wedge adjacent to the bladecarrier.
 13. The guarded surgical scalpel handle of claim 12 furthercomprising a blade defining a plane mounted to the blade carrier suchthat movement of the cantilever spring arm toward the blade carrier inthe plane of the blade urges the blade away from the blade carrier. 14.The guarded surgical scalpel handle of claim 13 wherein the bladeincludes a proximal end with a notch formed therein and the guardincludes a distal end with a complementary notch formed therein.